Related Media

LAKE TAHOE — At Lake Tahoe, goldfish are an invasive species. On the Internet, they’re viral.

Following a story by Sacramento TV station KCRA last week, hundreds of news outlets from around the world picked up the story about Lake Tahoe being home turf for giant goldfish.

And it’s true. Researches have known for years the aquarium dwellers are part of a warm-water fish invasion impacting native fish species and possibly the quality of Lake Tahoe’s near-shore environment.

Warm-water species have been documented in the lake as far back as the late 1970s. Largemouth bass and bluegill have been common to the Tahoe Keys development at the South Shore since the late 1980s.

But something about an oversized household pet impacting one of the world’s most famous lakes captured people’s imagination, said University of Nevada, Reno, spokesman Mike Wolterbeek.

“A giant goldfish is a lot sexier than a largemouth bass,” Wolterbeek said about the story’s global reach.

A Tuesday morning search of Google News showed nearly 500 articles about Lake Tahoe’s goldfish, including news outlets in England, Saudi Arabia and Pakistan. UNR limnologist Sudeep Chandra said he has received emails from as far away as Syria, Taiwan and Germany requesting information about the goldfish.

Goldfish varieties at Lake Tahoe can grow a foot or more in length and weigh several pounds. They are part of a species invasion that may be contributing to big changes in Lake Tahoe’s ecosystem, Chandra said. Brown bullhead and black crappie are among the non-native warm-water species found in the lake.

Warm-water fish species have been able to thrive in Lake Tahoe marinas because of the habitat provided by invasive aquatic weeds like milfoil. The species are also likely to have few predators, Chandra said.

The warm-water fish can out-compete native species for food, while also excreting nutrients into the near shore, possibly feeding algae blooms that have been a growing concern at the lake in recent years, Chandra said.

Researchers believe some of the species were introduced by fishermen planting species to catch. Pond or aquarium hobbyists dumping unwanted fish into the lake is likely the source of the goldfish.

Exactly when goldfish were introduced to Lake Tahoe is unknown. Will Richardson, co-founder of the Tahoe Institute for Natural Science, said he was surprised at the renewed interest in the fish. He said he first saw an osprey pluck a large goldfish from Pope Marsh around 2000.

Tahoe Regional Planning Agency spokeswoman Kristi Boosman said goldfish are only a small component of the warm-water fish issue at the lake. Other warm-water species, such as largemouth bass, may present a bigger threat to the lake’s food web, Boosman said.

The California Department of Fish and Wildlife, TRPA and UNR have partnered on a pilot project to remove warm-water fish species from the Tahoe Keys during the past two summers.

Of more than 22,000 non-native fish removed from the Keys in 2012, only a small fraction were goldfish, Boosman said.

“Really, they’re a blip in the big picture,” Boosman said.

The fish removal project is expected to continue this summer. Tahoe Keys Marina and the Tahoe Keys Property Owners Association have also been involved in the project, Wolterbeek said.

Researchers hope to have a better understanding of the numbers and movements of warm-water fish in the lake after this summer, Chandra said. Scientists are also on the lookout for a cold-water invader to the lake, smallmouth bass. Because they have limited knowledge of the whereabouts of the species in the lake, researchers are asking people to notify them if they see the fish, Chandra said. Smallmouth bass sightings can be reported to sudeep@cabnr.unr.edu.

Although taken back by the interest in Lake Tahoe’s goldfish, Chandra said the stories highlight examples of changes taking place in mountain lakes worldwide. He said he hoped the visibility of the goldfish would also help reveal a changing world and possibility prevent additional invaders from reaching Lake Tahoe.

“The take-home story here is don’t put plants and animals from your pond or aquarium into the lake,” Chandra said.

Adam Jensen is a staff writer for the Tahoe Daily Tribune, a sister publication to The Union.